Oxidation Of Cu Research Articles

Electrosynthesis and characterization of copper dicyanamide materials

X-ray diffraction and infrared reflection spectroscopy data have confirmed the electrosynthesis of copper dicyanamide films by cyclic voltammetry and potentiostatic electrolysis. An insoluble Cu(I)dca film can be synthesized on a gold or copper electrode by the reduction of Cu(II) or oxidation of Cu(0) in aqueous or methanolic solutions containing dicyanamide ions. By resorting to the use of the ruthenium hexaammine redox probe the Cu(I)dca film was shown to be electronically conductive although the deposition rate decreases when the film formation proceeds.Depending on the applied potential, not only Cu(I)dca but also Cu(II)dca can be formed by oxidation of a copper electrode in presence of dicyanamide ions dissolved in methanol. The powder obtained by electrolysis at 1 V vs Hg/Hg2SO4 made essentially of Cu(II)dca presents a specific surface area of (183 ± 59) m2/g. This material can adsorb preferentially methyl orange and Congo red dyes compared to methylene blue whereas no marked difference is obtained between CO and CO2 adsorption.

Electrodeposition of nanocrystalline Cu for Cu-Cu direct bonding

BackgroundCu-Cu direct bonding is a promising technology to construct a temperature resistant bonding structure for emerging power devices and vehicle electronics. The main challenge is the ease oxidation of Cu and slow solid-state atomic diffusion at the bonding surface. MethodsIn this study, nanocrystalline Cu is constructed on the bonding surfaces using electrodeposition and direct bonding is carried out in a formic acid atmosphere. Microstructural and strength analyses are performed to investigate the bonding performance of the Cu-Cu joints. Significant findingsThe bonding strength analysis indicates that a well-bonded Cu-Cu joint with a high shear strength of 71 MPa can be achieved by direct bonding of two Cu surfaces with a nanocrystalline structure (average grain size = 78 nm). Microstructural analysis shows that significant grain growth accompanying formation of twins at the bonding interface contribute to high bonding strength, which is attributed to enhanced atomic diffusion on the nanocrystalline Cu surfaces.

In-line detection of Cu+-related species in aged Cu plating bath using flow cell-based electrochemical method

• Method to analyze the concentrations of Cu + -related species in Cu plating bath is suggested. • The concentrations of Cu + -related species in a bath aged under open-circuit condition are evaluated. • The Cu + ion in the bath is stabilized by forming a complex with organic additives. Cu + -related species formed under electrolytic and open circuit conditions (e.g., Cu + and Cu + -3-mercapto-1-propane sulfonate (MPS)) are important intermediates that influence the performance of Cu-plating baths. However, trace amounts of Cu + -related species in the aged bath are difficult to analyze, thus making it increasingly difficult to ensure the performance of the bath. Here, an in-line and simple electrochemical method—based on a diffusion-limited current analysis of a 2-channel flow cell—was proposed to detect Cu + -related species in a bulk solution. Based on the voltammogram, in the range of 0.5–1.0 V, the aged bath possesses anodic currents related to the oxidation of Cu + -related complexes. The aged bath containing PEG revealed a single diffusion-limited current plateau at 0.5–1.0 V due to the oxidation of Cu + . In the presence of bis (3-sulfopropyl) disulfide, three current plateaus were observed, corresponding to the three-electron oxidation of the Cu(I)MPS complex. The concentrations of Cu + and Cu(I)MPS in the aged bath were evaluated using master calibration curves that were prepared based on simulation and experiment. The proposed method could be effectively utilized for the automated in-line monitoring of Cu electroplating baths.

Ratiometric ‘lightening up’ intracellular probe for Cu2+ and ClO− and applications for real time detection

The detection of Cu2+ and ClO− is important in many fields such as medical diagnostic and waste water treatment. The chromo-fluorescent probes have an edge over the traditional methods however few probes applied for dual detection of Cu2+ and ClO− ions. Herein, A new dual function ratiometric ‘turn-on’ chromo-fluorescent probe based on perylene tetra-(octyloxycarbonyl) dye containing N,N’-dimethylethylenediamine (PTAC-1) was synthesized and investigated for applications. It showed selective response for Cu2+ ions in CH3CN-H2O (7:3, v/v) with ratiometric absorption (A460nm/A521nm) and emission (F495nm/F660nm) changes with detection limits 94 nM and 2.5 nM, respectively. Dramatic colour changes in dye upon addition of 100 nM Cu2+ ions provide an excellent but rare example of visible naked eye detection. The inactive PTAC-1 + Cu+ mixture was used for the detection of ClO− via in-situ oxidation of Cu+ to Cu2+ with high selectivity. The detection limits were 374 nM and 6.09 nM. PTAC-1 was successfully used for bioimaging of Cu2+ and ClO− ions in MG-63 cells, developing solid- and solution-based diagnostic test kits for Cu2+ ions; for quantification of Cu2+ and ClO− ions in real samples including water, soil, urine and disinfectant. The complexation mechanism with Cu2+ or ClO− was confirmed by Job’s plot, SPECFIT, NMR, DLS titrations, IR, TGA and AFM studies.

Enhancement of catalytic combustion of toluene over CuMnOx hollow spheres prepared by oxidation method

Catalytic oxidation is considered as one of the most potential technologies for complete removal of VOCs. It is generally accepted that the development of catalyst with high and stable activity at low temperature is the key for such a catalytic strategy. The CuMnO x catalyst with a hollow spherical structure (CuMnO x -HS) was successfully prepared by an oxidation strategy and applied to toluene removal. Combined with the results of XRD, SEM, TEM, HRTEM, BET, H 2 -TPR, XPS and O 2 -TPD, the enhanced synergistic effect between Mn and Cu originating from the special oxidation method resulted in the large specific surface area, enhanced reducibility, and oxygen mobility as well as abundant adsorbed oxygen species of CuMnO x -HS, which was responsible for its superior catalytic performance. CuMnO x -HS could achieve a toluene conversion of 90% at 212 °C. Furthermore, CuMnO x -HS showed a stable removal efficiency and excellent water resistance, suggesting a great potential in practical application for the complete removal of toluene. CuMnO x catalyst with a hollow spherical morphology (CuMnO x -HS) was successively synthesized by in-situ oxidation of Cu 2 O nanospheres. The CuMnOx-HS catalyst achieves a toluene conversion of 100% at 220 °C, and shows super-stable removal efficiency and water resistance, indicating a great potential in practical application for the total oxidation of toluene. • CuMnO x hollow spheres (CuMnO x -HS) were prepared by in-situ oxidation of Cu 2 O. • The stepwise oxidation of Cu 2 O spheres facilitated the Cu 2+ -O 2− -Mn 4+ entities. • CuMnO x -HS showed a super-stable removal efficiency and good resistance to water. • The enhanced reducibility and oxygen mobility were responsible for the superior activity of CuMnO x -HS.

Artificial Chemical Nuclease and Cytotoxic Activity of a Mononuclear Copper(I) Complex and a Related Binuclear Double‐Stranded Helicate

AbstractCopper complexes are promising candidates for anticancer drugs, because of their redox properties and the ability to generate ROS (reactive oxygen species) in the cellular media. Most of the reported complexes with anticancer properties are based on Cu(II), which must be reduced to Cu(I) to exert the therapeutic action. Here, we report on the synthesis and characterization of two novel copper(I) complexes, a mononuclear complex [Cu(L1)2](ClO4) (1) and a binuclear helicate [Cu2(L2)2](ClO4)2 (2) (L1=2‐ethoxy‐1,10‐phenanthroline, L2=1,2‐bis((1,10‐phenanthrolin‐2‐yl)oxy)ethane), which were designed to be structurally comparable, in order to evaluate the effect of nuclearity on the artificial nuclease activity. The activity of helicate (2) was higher than that of the monometallic (1), and the DNA cleavage mechanism is through the generation of hydroxyl radical in a Fenton‐like reaction, which occurs after oxidation of Cu(I) by O2. Also, helicate (2) showed a higher cytotoxic effect against different cancer cells lines, while both complexes are more active than cisplatin.

Copper fluoride as a low-cost sodium-ion battery cathode with high capacity

Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries (LIBs) for large-scale energy storage considering the abundance and low cost of Na-containing resources. However, the energy density of SIBs has been limited by the typically low specific capacities of traditional intercalation-based cathodes. Metal fluorides, in contrast, can deliver much higher capacities based on multi-electron conversion reactions. Among metal fluorides, CuF2 presents a theoretical specific capacity as high as 528 mAh/g while its Na-ion storage mechanism has been rarely reported. Here, we report CuF2 as a SIB cathode, which delivers a high capacity of 502 mAh/g but suffers from poor electrochemical reversibility. As a solution, we adjust the cell configuration by inserting a carbon-coated separator, which hinders the transportation of dissolved Cu ions and improves the reversibility of the CuF2 cathode. By using in-situ XRD measurements and theoretical calculation, we propose that a one-step conversion reaction occurs during the discharge process, and a reconversion reaction competes with the oxidization of Cu to dissolved Cu ion during the charge process.

Evaluation of oxidation suppression of multilayer graphene synthesized using fluorene as a solid source

Multilayer graphene (MLG) on a Cu substrate was successfully fabricated via a solid-source chemical vapor deposition process using fluorene as the solid source. The surface coverage of graphene was greater than 98% even at 6 min, and the MLG ratio was ∼97%, indicating that our growth method selectively promoted MLG growth from the beginning of graphene growth. The oxidation suppression characteristics of MLG were confirmed using electron back-scattered diffraction (EBSD) analysis. Cu crystal orientations were identified only under areas covered by graphene, indicating that the oxidation of Cu did not proceed at the interface between Cu and graphene. We confirmed using EBSD techniques that MLG suppresses the surface oxidation of a Cu substrate. Furthermore, we showed that EBSD was an effective tool for evaluating surface oxidation as well as surface crystal orientations.

Chemical Vapor Deposition of N-Doped Graphene through Pre-Implantation of Nitrogen Ions for Long-Term Protection of Copper.

Nitrogen-doped graphene (NG) was synthesized through the chemical vapor deposition (CVD) of graphene on Cu substrates, which were pre-implanted with N ions by the ion implantation method. The pre-implanted N ions in the Cu substrate could dope graphene by the substitution of C atoms during the CVD growth of graphene, forming NG. Based on this, NG’s long-term protection properties for Cu were evaluated by ambient exposure for a corrosion test. The results showed that NG can obviously reduce the natural oxidation of Cu in the long-term exposure compared with the case of pristine graphene (PG) coated on Cu. Moreover, with the increase in pre-implanted N dose, the formed NG’s long-term protection for Cu improved. This indicates that the modification of graphene by N doping is an effective way to improve the corrosion resistance of the PG coating owing to the reduction in its conductivity, which would inhibit galvanic corrosion by cutting off electron transport across the interface in their long-term protection. These findings provide insight into corrosion mechanisms of the graphene coating and correlate with its conductive nature based on heteroatoms doping, which is a potential route for improving the corrosion resistance of graphene as an effective barrier coating for metals.

Catalytic oxidation of CO in gases emitted by industrial processes and vehicle exhaust

A new type of catalysts not containing noble metal oxides have been developed and the possibilities of their application both for the complete neutralization of carbon monoxide in exhaust gases and the process of deep oxidation of volatile hydrocarbons are studied. It has been foundthatthe activity of catalysts based on vanadiumandphosphorus oxides supported on Al2O3, SiO2, TiO2by and their modification withof 1–3% oxides of Cu, Cr, Co, Zn enhanced the conversion of the deep oxidation process to 95–100% at the temperatures of 673–693K and volumetric velocities of 5000–10000 h–1. During the simultaneous oxidation of CO and C3H8at a CO conversion of 90%, the C3H8conversionwas 70%. It has been established that oxidation of CO and C1–C4 hydrocarbons, and especially propane, with the participation of synthesized catalytic series, occurs by stepwise and associative mechanisms. The oxidation of CO and C3H8required a high oxygen content of 1:20–25 mol. Besides utilizing carbon monoxide in exhaust gases from motor vehicles, these catalytic systems can be successfully used to neutralize industrial gases, especially those emitted from oil refineries and thermal power plants. Preliminary research has shown that these catalytic systems can operate for about 50000 hours without changing the activity.

Capacitive-faradaic fuel cells (CFFCs) for selective separation of copper(II) ions from water and wastewater

• The mechanism of Cu 2+ ions removal from water by the CFFCs was studied. • Cu 2+ are catalytically reduced to Cu 0 by H 2 on the Pt within the separation step. • The Cu 0 is oxidized by oxygen within the regeneration step. • The electrosorption mechanism is insignificant in Cu 2+ separation by the CFFCs. • Cu 2+ ions are selectively separated from Ni 2+ , Cd 2+ , Fe 3+ , Ca 2+ , Mg 2+ and Zn 2+ . The capacitive-faradaic fuel cells (CFFCs), previously proposed for separation of anions and cations from water and wastewater, were investigated for Cu 2+ ions removal. It is shown in this study that the electrosorption of copper ions plays an insignificant role in the process and the major mechanisms that govern the H 2 -induced Cu 2+ separation and the O 2 -induced regeneration of the CFFCs are ( i ) catalytic reduction of Cu 2+ ions into the elemental copper (Cu 0 ), and ( ii ) oxidation of Cu 0 into Cu 2+ ions, respectively. The process was investigated in pure CuCl 2 solutions at different pH values with an activated granular charcoal on which different loadings of Pt catalyst were embedded (0, 0.1, 0.25, 0.5, 1.0 and 2.5 %wt.). Higher adsorption density of Cu was obtained at higher Pt loading (i.e., 30 mgCu/gCFFCs in 0.1%Pt-CFFCs and 75 mgCu/gCFFCs in 2.5%Pt-CFFCs), but the Pt-utilization efficiency decreased from 30 mgCu/mgPt in 0.1%Pt-CFFCs to 3 mgCu/mgPt in 2.5%Pt-CFFCs. Better Cu 2+ removal was achieved at higher pH due to lower reversible potential of the hydrogen oxidation reaction. Excellent selectivity of the process for Cu 2+ ions removal was obtained in experiments conducted with aqueous solution that comprised Cu 2+ , Ni 2+ , Cd 2+ , Fe 3+ , Ca 2+ , Mg 2+ and Zn 2+ ions (100 mg/l each). Further studies are required to develop the CFFCs with ultralow Pt loading or/and to replace Pt with non-noble metal catalysts.

Chelation-mediated synthesis of nanoporous gold at near-neutral pH and room temperature by free corrosion dealloying of gold-copper alloy driven by oxygen reduction

Dealloyed nanoporous gold (NP-Au) is commonly created with hazardous chemicals including strong oxidizing acids. This work presents a green alternative to the common methods for making NP-Au. In this work, we create NP-Au by free corrosion dealloying of a Au-Cu parent alloy at room temperature in a near-neutral pH aqueous solution of ethylenediaminetetraacetic acid (EDTA), a non-toxic chelating ligand. The oxygen reduction reaction (ORR), catalyzed by activated carbon cloth (ACC), is employed to drive selective oxidation of Cu into Cu2+ ions, and EDTA is used to sequester the Cu2+ ions, preventing passivating copper oxide (CuOx)-forming reactions. We call this methodology chelation-mediated dealloying. Using small-angle x-ray scattering (SAXS), x-ray diffraction (XRD), and scanning electron microscopy (SEM), we observe that the NP-Au produced under mild conditions is similar to that produced by free corrosion dealloying in nitric acid (HNO3), a highly hazardous and strong oxidizing acid.

Antimony allotropes fabricated on oxide layer of Cu(111)

Monolayer and few layer antimony allotropes fabricated on oxide layers are essential for practical applications in fields of solar cells, electronic and photonic devices. Here the antimony structural phases are systemically studied on corrugated copper oxide of Cu(111) by atomically-resolved scanning tunneling microscopy (STM). We find that initial deposition of Sb atoms causes the structural changes of the underlying oxide layer and sequentially gives rise to the formation of flat (√7 × √7)-Sb and buckled antimonene phases. Finally, a nanoring-like antimony configuration is observed with triangle-shaped atomic arrays closely packing and shows high stabilities for oxygen exposure. The (√7 × √7) phase exhibits the metallic property with energetically continuous electronic states existing near Fermi level. For the antimonene and nanoring phases, band gap signatures are observed, implying the semiconducting features. Our results provide a method for fabricating stable elemental allotropes on oxide surfaces.

Use of Copper as a Trigger for the in Vivo Activity of E. coli Laccase CueO: A Simple Tool for Biosynthetic Purposes.

Laccases are multi‐copper oxidases that catalyze the oxidation of various electron‐rich substrates with concomitant reduction of molecular oxygen to water. The multi‐copper oxidase/laccase CueO of Escherichia coli is responsible for the oxidation of Cu+ to the less harmful Cu2+ in the periplasm. CueO has a relatively broad substrate spectrum as laccase, and its activity is enhanced by copper excess. The aim of this study was to trigger CueO activity in vivo for the use in biocatalysis. The addition of 5 mM CuSO4 was proven effective in triggering CueO activity at need with minor toxic effects on E. coli cells. Cu‐treated E. coli cells were able to convert several phenolic compounds to the corresponding dimers. Finally, the endogenous CueO activity was applied to a four‐step cascade, in which coniferyl alcohol was converted to the valuable plant lignan (−)‐matairesinol.

Cupric oxide (CuO)/zinc oxide (ZnO) heterojunction diode with low turn-on voltage

The p-n junction is the fundamental form of an electronic semiconductor device. A p-CuO/n-ZnO heterojunction diode was formed by using thermal evaporation and thermal oxidation techniques. Cupric oxide (CuO) films of 300 µm in thickness were obtained by thermal oxidation of Cu foils. Zinc oxide (ZnO) films of 30 µm in thickness were prepared in two process steps: firstly, thermal evaporation of Zn at atmospheric pressure, and then thermal oxidation to Zn films. The p-CuO/n-ZnO heterojunction diode was formed by performing the steps of ZnO deposition on the surface of the CuO films, and completed by deposition of silver electrical contacts on the top and on the bottom sides of the heterostructure. Structural, morphological, and electrical properties of CuO and ZnO were studied by X-ray diffraction (XRD), Raman spectroscopy, Uv–Vis DRS, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Hall effect techniques. Current-voltage (I-V) measurements were performed to the p-CuO/n-ZnO heterojunction diode. Structural characterization to CuO confirmed that pure, crystalline and (111) textured films can be obtained by thermal oxidation of Cu. ZnO films showed a polycrystalline structure without preferred orientation. The band gap of CuO and ZnO were 1.51 and 3.21 eV, respectively. Cross-sectional SEM and TEM images confirmed the formation of the p-CuO/n-ZnO heterojunction diode. Hall measurements confirmed the p-type conductivity of CuO and the n-type conductivity of ZnO. Also, the carrier concentration and Hall mobility of CuO films were 9.54 × 1012 cm−3 and 267 cm2 V−1 s−1, respectively. ZnO films exhibited a carrier concentration and Hall mobility of 3.69 × 1012 cm−3 and 22.18 cm2 V−1 s−1, respectively. The I-V measurement showed that the p-CuO/n-ZnO heterojunction exhibits a low turn-on voltage of about 0.8 V and a breakdown voltage of about 38 V. Electrical parameter such as rectification ratio and ideality factor were also calculated. An energy band-diagram of the CuO/ZnO heterojunction was proposed, where a built-in voltage of 0.57 eV was observed.

Effect of Lining Papers on the Permanence of Painting Papers in Japanese Scroll Paintings During Moist Heat Ageing

ABSTRACT A Japanese painting paper is sized with an aqueous solution of alum and animal glue followed by brushing with a mixture of pigments of various colours and aqueous animal glue solution. Subsequently, to mount the Japanese painting to a hanging scroll, the backside of the painting is lined with a first lining paper using wheat starch paste for mechanical support. To evaluate the permanence of the painting paper as a composite material in the hanging scroll, the deterioration behaviour of the unlined painting paper and the lined painting paper was compared considering the material dynamics. After moist heat accelerated ageing (80°C, 65% RH), in the sample immersed in a CuSO4・5H2O solution, cellulose was oxidised by Cu2+ to generate organic acids in the painting paper, and Cu2+ and organic acids migrated to the lining paper. Consequently, the discolouration and oxidation of the painting paper in the lined complex were relatively low compared with those of the unlined painting paper. The pH decrease in the painting paper was also small in the lined complex. Moreover, if the animal glue solution was coated on the painting paper, a buffer effect was shown to operate against the organic acids derived from the oxidation of Cu2+, thereby inhibiting the migration of Cu2+ into the lining paper. In conclusion, the presence of the lining paper inhibited the decrease in the physical strength and degree of polymerisation of the cellulose in the painting paper, thus contributing to its permanence in the lined hanging scroll.

In-air sintering of copper nanoparticle paste with pressure-assistance for die attachment in high power electronics

There is a high demand for the implementation of metallic nanoparticle (NP) sintering technology for die attach in high-power electronics. The performance of this technology is superior to that of the technology involving the use of lead-free solders. Although Cu NP paste is potentially a low-cost material, it faces the challenge of oxidation during sintering. This may result in a significant deterioration of the mechanical, thermal, and electrical properties. Therefore, there are limited studies on the in-air sintering of Cu NP pastes. The present study demonstrated the in-air pressure-assisted low-temperature sintering of a commercial Cu NP paste. Furthermore, the sintering was performed without using a protective atmosphere, unlike that in most of the previously reported investigations. The sintering behavior was investigated at three levels of temperatures (200–240 °C) and five levels of pressures (5–25 MPa). The joints that were sintered at high temperatures and pressures exhibited condensed microstructures and high bonding strengths. High sintering temperatures accelerated the diffusion between Cu NPs, while high sintering pressure facilitated the removal of evaporated organic compounds and the air between NPs. This not only facilitated sintering but also prevented the oxidation of Cu. The optimal sintering conditions promoted the formation of 3D connections between the Cu NPs, thereby increasing the shear strength of the sample. The samples that were sintered at 240 °C and 10 MPa experiences the highest increase in the shear strength, furthermore, the microstructures were optimized under this condition. The shear strength of 28.1 ± 8.47 MPa was achieved under this condition, which satisfied the requirements for die attach in high power electronics applications, moreover, the sintering process was moderate and cost-effective. Therefore, the optimal sintering temperature and pressure for the in-air sintering of the Cu NP paste was concluded to be 240 °C and 10 MPa, respectively. The results indicated that in-air sintering with pressure assistance can be applied for die attach in the high-power electronics.

Characterizing armchaired and zigzagged phases: Antimony on oxide layer of Cu(110)

Antimony nanostructures fabricated on metal oxide layers are essential for practical applications in fields of solar cells, electronic and photonic devices. Here the antimony phases were systemically studied on the copper oxide of Cu(110). By high-resolution scanning tunneling microscopy (STM), we revealed that a wrinkled antimony phase was formed on the CuO surface regardless of the initial oxide structure. It exhibited an armchair-like configuration making up of protruded and dipped Sb atoms as confirmed by STM and density functional theory calculations. Further Sb deposition caused the armchair-like phase distorting and subsequently gave rise to formation of a c(2 × 2)-Sb phase. Finally, another kind of wrinkled phase was successfully fabricated. It consisted of two zigzagged antimony chains with protruded and dipped Sb atoms alternately distributing. By analysis of the atomically-resolved STM topographies, several kinds of dislocations have been observed and the corresponding geometric models are addressed. The armchair and zigzag phases both exhibited high stabilities for oxygen exposure. Conductance measurements imply that each phase interacts with the underlying layer. Our results might provide a way for fabricating stable ultrathin materials with a well-defined edge structure on oxide surfaces.

Selective catalytic reduction of NO over Cu-AFX zeolites: mechanistic insights from in situ/operando spectroscopic and DFT studies

In situ/operando spectroscopic experiments and DFT calculations unravel the redox mechanism of NH3-SCR over Cu-AFX zeolites.

Plasma-assisted oxidation of Cu(100) and Cu(111).

Oxidized copper surfaces have attracted significant attention in recent years due to their unique catalytic properties, including their enhanced hydrocarbon selectivity during the electrochemical reduction of CO2. Although oxygen plasma has been used to create highly active copper oxide electrodes for CO2RR, how such treatment alters the copper surface is still poorly understood. Here, we study the oxidation of Cu(100) and Cu(111) surfaces by sequential exposure to a low-pressure oxygen plasma at room temperature. We used scanning tunnelling microscopy (STM), low energy electron microscopy (LEEM), X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and low energy electron diffraction (LEED) for the comprehensive characterization of the resulting oxide films. O2-plasma exposure initially induces the growth of 3-dimensional oxide islands surrounded by an O-covered Cu surface. With ongoing plasma exposure, the islands coalesce and form a closed oxide film. Utilizing spectroscopy, we traced the evolution of metallic Cu, Cu2O and CuO species upon oxygen plasma exposure and found a dependence of the surface structure and chemical state on the substrate's orientation. On Cu(100) the oxide islands grow with a lower rate than on the (111) surface. Furthermore, while on Cu(100) only Cu2O is formed during the initial growth phase, both Cu2O and CuO species are simultaneously generated on Cu(111). Finally, prolonged oxygen plasma exposure results in a sandwiched film structure with CuO at the surface and Cu2O at the interface to the metallic support. A stable CuO(111) surface orientation is identified in both cases, aligned to the Cu(111) support, but with two coexisting rotational domains on Cu(100). These findings illustrate the possibility of tailoring the oxidation state, structure and morphology of metallic surfaces for a wide range of applications through oxygen plasma treatments.